We report laboratory measurements of the Zeeman response of lines in the 0-0 Wing-Ford band of the F-X system (λ ~ 1 μm) of FeH, measured in magnetic fields 0.3 – 0.5 Tesla. New Landé factors are used to deduce the magnetic field in sunspots from Stokes V profiles recorded at the solar telescope THEMIS. The magnetic field deduced from atomic lines (Ti, Fe) is slightly higher than that found from FeH.

Magnetic fields of cool stars can be directly investigated through the study of the Zeeman effect on photospheric spectral lines using several approaches. With spectroscopic measurement in unpolarised light, the total magnetic flux averaged over the stellar disc can be derived but very little information on the field geometry is available. Spectropolarimetry provides a complementary information on the large-scale magnetic topology. With Zeeman-Doppler Imaging (ZDI), this information can be retrieved to produce a map of the vector magnetic field at the surface of the star, and in particular to assess the relative importance of the poloidal and toroidal components as well as the degree of axisymmetry of the field distribution.

The development of high-performance spectropolarimeters associated with multi-lines techniques and ZDI allows us to explore magnetic topologies throughout the Hertzsprung-Russel diagram, on stars spanning a wide range of mass, age and rotation period. These observations bring novel constraints on magnetic field generation by dynamo effect in cool stars. In particular, the study of solar twins brings new insight on the impact of rotation on the solar dynamo, whereas the detection of strong and stable dipolar magnetic fields on fully convective stars questions the precise role of the tachocline in this process.

Sun-like stars are able to continuously generate a large-scale magnetic field through the action of a dynamo. Various physical parameters of the star are able to affect the dynamo output, in particular the rotation and mass. Using the NARVAL spectropolarimeter (Observatoire du Pic du Midi, France), it is now possible to measure the large-scale magnetic field of solar analogues (i.e. stars very close to the Sun in the mass-rotation plane, including strict solar twins). From spectropolarimetric time-series, tomographic inversion enables one to reconstruct the field geometry and its progressive distortion under the effect of surface differential rotation. We show the first results obtained on a sample of main-sequence dwarfs, probing masses between 0.7 and 1.4 solar mass and rotation rates between 1 and 3 solar rotation rate.

We report a preliminary study of the main focal plane instrument for the IRAIT telescope, currently being built at INAF-Astronomical Observatory of Teramo. The basic requirements are those of a remotely-controlled camera aimed to perform 10- and 20-μm photometry from Dome-C in the standard bandpasses N and Q. Starting from the site properties and the science goals, the main components of AMICA (Antarctic Mid-Infrared CAmera) are described: a Si:As BIB array detector, sensitive in the range 2–28 μm; a fully reflective optical design; a cryostat modified in order to work at the extreme environmental conditions of the antarctic plateau; a cryocooler maintaining the operating temperature of 4.2 K without external intervention; an automatized and flexible control electronics.
AMICA is designed to fully exploit the unique mid-infrared observing conditions at Dome-C.

Helioseismology and Asteroseismology have already given important contributions to stellar astrophysics, and they provide a powerful diagnostic method to improve our knowledge about the interior and evolution of star. Some experimental problems, however, such as the atmospheric scintillation, affect the precision of the measurements we can achieve. This kind of noise can ultimately be eliminated only through space-based observation, at the expense of high organization and financial costs. In the framework of a collaboration between the Solar Physics Laboratory (G28) of University of Rome La Sapienza and the Brera Astronomical Observatory of Milan-Merate, an experimental set-up has been developed to increase the signal to noise ratio of our photometric observations and reduce the scintillation noise. This system appears to be a great help in observational asteroseismology as it strongly rejects the scintillation noise while amplifies the stellar signals. Dome-C would be the best ground based site for our measurements because of its low scintillation noise level and high atmospheric stability.

The Concordia Station (Candidi 2003), on the Antarctica Plateau, will soon become one of the best observatories to perform infrared observations in the 2–20 μm atmospheric windows and beyond, thanks to its low sky background, low temperature and high atmospheric transparency. The possibility of passively cooling the telescope is a further advantage. We describe here the first permanent Antarctic infrared telescope, under development for the Dome C base. It is the International Robotic Antarctic Infrared Telescope (IRAIT). We briefly outline a few scientific motivations for it, then we review the technical characteristics and the status of its development. The infrared camera for IRAIT is described in another dedicated paper in this volume.

Accompanying the development of the PACS photometer camera (60–210 μm) on the Herschel Space Observatory, CEA/SAp and CEA/LETI have developed a new type of filled bolometer arrays. We present a camera using these “CCD-like” detectors for ground-based submillimeter applications. Such an instrument could potentially be operated in all atmospheric windows between 200 and 870 μm on a submillimetre-wave single-dish telescope at Dome C. A bolometer array could consist of several monolithic units of 16 × 16 pixels (as an example the blue and red PACS arrays consist of 4 × 2 and 2 × 1 units, respectively), providing a full sampling of the focal plane.

We study the potential impact of a photometric search for transiting exoplanets from Dome C. In the past year, four new transiting exoplanets have been found by ground-based surveys, including three detected by our follow-up of OGLE transit candidates with FLAMES/UVES on the VLT. Based on the experience of this survey, we have built a simulation to predict the expected number of transiting exoplanet detections from photometric searches. We apply these simulations to a possible survey based at Concordia. We find that the Antarctica location solves the two main limitations of ground-based transit surveys: the diurnal-cycle time sampling, and the hour-timescale systematic photometric variations. The expected numbers of detections are much larger than for other ground-based surveys. They show the high potential of such projects at Dome C, even with a small telescope.

PILOT (Pathfinder for an International Large Optical Telescope) is a proposed 2 m class optical/infrared telescope to be sited at Dome C on the Antarctic plateau. Recent site testing results from Dome C have shown remarkable ground level seeing, a large isoplanatic angle, and a long atmospheric coherence time. These factors significantly improve the resolution and increase the capabilities of adaptive optics systems. Additionally, the low sky emission at Dome C gives a significant increase in infrared sensitivity compared to typical mid-latitude sites. PILOT is envisaged as a winterised version of a commercially available 2 m class telescope, with a simple low cost dome (sufficient for the low ground level wind speeds), and a tip-tilt and/or a deformable secondary mirror. A number of science cameras covering the visible to the sub-millimetre are being considered.

We present the scientific case for a high resolution spectro-imager in the mid-IR that would be dedicated to the mapping of H2 emission in its four lowest rotational transitions, at 28.2, 17.0, 12.3 and 9.7 micron with a spectral resolution ~104 sufficient to provide kinematical distances in galaxies. The proposed instrument on a 2 m-class telescope will be most sensitive to H2 line emission simultaneously extended and structured at small scale, in gas at temperatures higher than 80 K. Colder H2, which may contribute most of the baryonic dark matter in galaxies, will be traced by the emission of glitters of warm H2 heated, throughout the medium, by the dissipation of omnipresent turbulence. The main scientific objectives are to (i) directly measure the mass and temperature distribution of the warm H2, far from star forming regions, in particular in low metallicity environments where the traditional tracers of H2 (CO, dust emission) fail, (ii) trace the dissipation of turbulence in the perspective of building a global view of the star formation process in galaxies and (iii) trace baryonic dark matter in the form of cold H2 in a large sample of galaxies along the Hubble sequence.

We present results of daytime site testing at Dome C in summer 2003–2004. Daytime seeing has been monitored during 2$\frac{1}{2}$ months using a DIMM on the bright star Canopus, giving median value of 0.54 arcsec. An every-day best seeing period has been observed around 5 pm with seeing around 0.3 arcsec. First isoplanatic angle measurements, based on stellar scintillation, were also performed during the month of January 2004, and have given median value of 6.8 arcsec.


The ClOVER instrument (described elsewhere in this volume) is being built to measure the B-mode polarisation of the Cosmic Microwave Background. Each of the 256 pixels is made up a pseudo-correlation receiver that can be realised using either waveguide or microstrip technology. In this work we present a design study for a possible waveguide-based solution. Each of the individual components has been optimised using electromagnetic finite-element modelling software (HFSS).

We launched a program to recover cosmic dust (micrometeorites) from Dome C surface snow near the French-Italian station CONCORDIA. The Dome C snow is uniquely shielded from both morainic debris and aeolian dust within the micrometeorite size range (≥25 μm). The average temperature at Dome C ranges from -20°C to -75°C throughout the year. Once trapped in a cold and clean snow, the micrometeorites are expected to stay much better preserved from mechanical constraints and less altered by terrestrial weathering than those of previous collections (mainly from Antarctic blue ice fields). We carried out 2 field expeditions in January 2000 and January 2002 using a new collection technique at Dome C. We successfully recovered micrometeorites from surface snow layers. By contrast with previous collections of micrometeorites, the particles from the CONCORDIA-Collection have suffered very little from terrestrial weathering. They have well constrained terrestrial ages. Their periods of fall overlap the ones of the particles found in the stratospheric interplanetary dust collections (IDPs) made by NASA. Because the precipitation rate is extremely low at Dome C, it is technically possible to exploit large areas (several tens of m2 year) of annual snow layers formed up to 3 centuries ago, which allows searching for cometary particles from historical meteor showers.

Recent advances in bolometric detector technology have allowed submillimetre (submm) wavelength measurements to contribute important data to some of the most challenging questions in observational cosmology. The availability of large-format filled-array cameras during the next decade, however, promises to provide far-infrared (FIR) to millimetre (mm) observations with unprecedented imaging fidelity. The simultaneous increase in the telescope collecting area of new facilities, and their location at ground-based sites with the highest atmospheric transmission will provide observational data with greater sensitivity and resolution. With the opening of the Italian/French Concordia station at Dome C in Antarctica there is now an exciting opportunity to make unique FIR–submm wavelength observations (200–850 μm) through atmospheric windows that are almost open to space. The development of submm astronomy from Dome-C, undertaken with a phased-programme of increasingly larger telescopes, will make critical observations of the high-redshift universe. In particular, we argue that a long-term strategy for Dome C should include plans to construct a 30-m telescope with a large field-of-view (≥0.1 sq deg), designed and optimized to operate at ~200 μm. With such a single-dish facility it will be possible to resolve 100% of the population of galaxies that contribute to the integrated FIR-submm extragalactic background. In this paper we describe how a large-aperture submm telescope at Dome C will provide unique data to address fundamental questions and killer science regarding the evolutionary history, nature and large-scale distribution of the population of high-redshift optically-obscured starburst galaxies

The high Antarctic plateau is considered as the best observing site on Earth in the sub-mm and mm bands. Dome C is one of the most elevated all-year-round station in this continent. Due to its peculiar location, it is also characterized by low wind speeds and very low precipitable water vapor contents. Some experiments have been brought there since 1995 and some ancillary data have been recorded. We report here the actual status of the site quality knowledge in the sub-mm and mm bands.

Recent results of asteroseismology have been achieved on a growing list of solar-type stars thanks to high precision echelle spectrographs. These results indicates that Doppler measurements are more efficient from the ground than photometry for p-modes detections. A high precision spectrograph dedicated for Doppler asteroseismology based in Dome C will play an important and fundamental step in asteroseismology. Such an instrument coupled to an only 1-m class telescope will be able to reach a very high level of sensibility for p-mode detection on several tens of solar-type stars. Capabilities and expected performances in asteroseismology of a replica of the SOPHIE spectrograph (1.93-m OHP) based in Dome C are presented. Such an instrument is furthermore fully compatible and adapted for polarimetry studies and detection and characterization of extra-solar planets.

The Permanent All Sky Survey (PASS) is a project for a continuous photometric survey of the entire celestial sphere with a high temporal resolution. Its major objectives are the detection of all giant-planet transits (with periods up to some weeks) across stars up to mag 10.5, and the delivery of continuous time series photometry that is useful for the study of any variable stars. For a southern instrument of PASS, Dome C offers two major advantages over mid-latitude sites: lower noises and greatly improved observational coverage. The simplicity of the instrument should make it fairly easily adaptable to the extreme low temperatures at that site.

Among the various recombination schemes devised for nulling interferometry, one is to use the Achromatic Interfero Coronograph (AIC) which basically is a modified Michelson-Fourier interferometer made compact by cementing together optical components. The principle of this AIC is based on the focus-crossing property, from which a wave of light experiences an achromatic π phase shift when crossing a focus. Operated up to now only on a single telescope, this device is able to accomodate several beams for nulling. We describe the use of AIC as an interferometric nuller for a two-aperture interferometer.

A large fraction of the energy released during solar flares is carried by accelerated electrons and ions. At present the most direct diagnostics of accelerated electrons are the radio emission produced from the microwave to the sub-millimeter domains by gyrosynchrotron emission and the hard X-ray/gamma-ray continuum from electron bremsstrahlung. These diagnostics have brought valuable information on the electron energetics, but the characteristics of relativistic electrons are still poorly known, although they provide the most stringent constraints for acceleration models. This is, at least partly, because radio diagnostics were usually obtained below 100 GHz and gamma-ray measurements were restricted to energies below 100 MeV. Recent radio observations in the 200–400 GHz range have revealed a new spectral component, the origin of which is not yet understood. Observations at higher frequencies are necessary in order to discriminate between different possibilities. Although solar observations in the far infrared domain have not yet been performed, this spectral region contains key information on both relativistic electrons and the response of the low atmosphere to energy deposition from the flare. The combination of observations obtained in the far infrared continuum (2–10 THz) with measurements of high energy gamma-rays (up to 500–600 MeV) will not suffer from the limitations of the present diagnostics and thus provide new constraints on acceleration and energy transport processes.

PLANET, the Probing Lensing Anomaly NETwork, is an international team conducting observations of on-going gravitational microlensing events from five sites in the southern hemisphere. Our primary goal is to detect or to put constraints on sub-stellar companions of M dwarfs from the galactic disk. We report the current status and discuss the future prospects. A 2 m robotic telescope at Dome C which would benefit from continuous coverage and dream like seeing (median of 0.27 arcsec) is currently the best option for a ground based aggressive search for Earth-mass planets in the habitable zone.